"This was not an easy re-entry to predict because of the natural forces acting on the satellite as its orbit decayed. Space-faring nations around the world also were monitoring the satellite's descent in the last two hours and all the predictions were well within the range estimated by JSpOC."

UARS was launched aboard space shuttle Discovery in 1991. Nasa decommissioned the satellite in 2005, after moving it into a lower orbit that cut its life short by two decades.

Bits of space junk re-enter the atmosphere virtually every day. No injuries have ever been reported from it.